Below are some interesting comments from Miles Abernathy's Sewer List. Information about this list group (~500 members) can be found at http://www.swopnet.com/engr/mail_lists/sewer_list_info.html
Paul
I'm doing preliminary research on the costs of crossing a 1,500 ft stretch of open water (narrow part of lake) with a 33" wastewater line. None of the contractors in my area have experience in doing such a large crossing and I'm looking for resources that can help me with a rough cost estimate for trenchless, trenching, and bridging options.
Any help is greatly appreciated.
Because what you are really looking for are installation costs (you know your material costs), you really should be talking with contractors. They can come up with some pretty ingenious methods for doing this. A fellow I worked with a number of years ago told me of a contractor that came in very low on a bid for similar work. They waited until the dead of winter (this was in the northern US) and laid the pipe out on a frozen lake. After the ice began to break up in spring, they slowly lowered the pipe to the bottom of the lake. The installation went fine and tested well. You need to be aware of some means of installing the line, it has to be contructable, but I wouldn't restrict the contractor to specific means and methods. If contractors in your area aren't experienced with laying the line you need, contact contractors outside your general area to get a price. For things that are a bit out of the ordinary, expect prices to be all over the place.
I'd suggest you investigate into horizontal directional drilling.
33" now there is a handy size.
Tom makes a good suggestion.
The HDD suggestion is also good.
If you decide to put the pipe on the bottom on the lake I recommend US
Pipe, Usiflex pipe.
You might check with the local US Pipe rep for assistance.
A word of caution,
I worked for an agency once that had a 6" sewage force main line across about 500' of a lake arm. When the developer put the line in there wasn't any public around. 20 years later both sides of the lake are developed with a lot of people that had a lot of time on their hands.
The lake has a bad habit of growing a nasty looking algae blob/glob late in the summer when the water heats up, don't you just love mother nature. The people with a lot of time on their hands are convinced that the sewer line is leaking and causing the blob/glob to grow. The blob/glob is tested, results are that it is algae.
People show up at Board meetings, the agency starts pressure testing the line twice a year for several years. All the test results show that the line is not leaking, the pipe is US Pipe, Usiflex.
More people show up a Board meetings, the result being that the agency caved in to the public pressure and did a project to take the sewage around the lake arm, 12,000 feet of line and a new pump station.
The sewer line in the lake was abandoned in place and still has sewage setting in it.
The lake still grows blob/glob every summer, but the public is happy!!
Just a word of caution, Received on Fri Oct 22 20:12:00 2004
This archive was generated by hypermail 2.1.8 : Mon Oct 27 2008 - 20:24:05 EDT